A Memorandum of Cooperation signed on July 17, 2008 by provincial ministers and Ontario Representatives of the Great Lakes and St. Lawrence Cities Initiative commits Ontario to consulting and cooperating on issues of municipal interest and responsibility around the Great Lakes.

The Memorandum is a formal recognition of the engagement of municipalities as stakeholders in the health of the Great Lakes. A recent study estimates that local governments around the Great Lakes and St. Lawrence River Basin in Canada and the U.S. invest $15 billion annually in infrastructure and programs to protect the Great Lakes and St. Lawrence River.

In it, Ontario agrees to consider the advice and recommendations of the Cities Initiative and the Cities Initiative agrees to involve its Ontario members and the broader municipal sector in providing input into decisions that affect municipalities.